hierarchical_weight_resolution_test

TE-3.3: Hierarchical weight resolution

Summary

Ensures that next-hop weights (for WCMP) are honored hierarchically in gRIBI recursive resolution and traffic is load-shared according to these weights.

Procedure

Configure ATE and DUT:

• Connect ATE port-1 to DUT port-1. ATE port-2 to DUT port-2.

• Create a non-default VRF (VRF-1) that contains no interfaces.

• On DUT port-2 and ATE port-2 create 18 L3 sub-interfaces each with a /30 subnet as below:

  • On DUT port-2, create subinterfaces with indices 1 to 18 mapped to VLAN IDs 1 to 18 and corressponding IPv4 addresses 192.0.2.5, 192.0.2.9, ..., 192.0.2.73 respectively.

  • On ATE port-2, create subinterfaces with indices 1 to 18 mapped to VLAN IDs 1 to 18 and corresponding IPv4 addresses 192.0.2.6, 192.0.2.10, ..., 192.0.2.74 and default gateways as 192.0.2.5, 192.0.2.9, ..., 192.0.2.73 respectively.

• On DUT port-1 and ATE port-1 create a single L3 interface.

• On DUT, create a policy-based forwarding rule to redirect all traffic received from DUT port-1 into VRF-1 (based on src. IP match criteria).

Test case for basic hierarchical weight:

• Establish gRIBI client connection with DUT with PERSISTENCE, make it become leader and install the following Entries:

  • IPv4Entry 203.0.113.0/32 in VRF-1, pointing to NextHopGroup(NHG#1) in default VRF, with two NextHops(NH#1, NH#2) in default VRF:

    • NH#1 with weight:1, pointing to 192.0.2.111

    • NH#2 with weight:3, pointing to 192.0.2.222

  • IPv4Entry 192.0.2.111/32 in default VRF, pointing to NextHopGroup(NHG#2) in default VRF, with two NextHops(NH#10, NH#11) in default VRF:

    • NH#10 with weight:1, pointing to 192.0.2.10

    • NH#11 with weight:3, pointing to 192.0.2.14

  • IPv4Entry 192.0.2.222/32 in default VRF, pointing to NextHopGroup(NHG#3) in default VRF, with two NextHops(NH#100, NH#101) in default VRF:

    • NH#100 with weight:3, pointing to 192.0.2.18

    • NH#101 with weight:5, pointing to 192.0.2.22

• Validate with traffic:

  • NH10: (1/4) * (1/4) = 6.25% traffic received by ATE port-2 VLAN 1

  • NH11: (1/4) * (3/4) = 18.75% traffic received by ATE port-2 VLAN 2

  • NH100: (3/4) * (3/8) = 28.12% traffic received by ATE port-2 VLAN 3

  • NH101: (3/4) * (5/8) = 46.87% traffic received by ATE port-2 VLAN 4

  • A tolerance of 0.2% is allowed for each VLAN for now, since we only test for 2 mins.

Test case for hierarchical weight in boundary scenarios, with maximum expected WCMP width of 16 nexthops:

• Flush previous gRIBI Entries for all NIs and establish a new connection with DUT with PERSISTENCE and install the following Entries:

  • IPv4Entry 203.0.113.0/32 in VRF-1, pointing to NextHopGroup(NHG#1) in default VRF, with two NextHops(NH#1, NH#2) in default VRF:

    • NH#1 with weight:1, pointing to 192.0.2.111

    • NH#2 with weight:31, pointing to 192.0.2.222

  • IPv4Entry 192.0.2.111/32 in default VRF, pointing to NextHopGroup(NHG#2) in default VRF, with two NextHops(NH#10, NH#11) in default VRF:

    • NH#10 with weight:3, pointing to 192.0.2.10

    • NH#11 with weight:5, pointing to 192.0.2.14

  • IPv4Entry 192.0.2.222/32 in default VRF, pointing to NextHopGroup(NHG#3) in default VRF, with 16 NextHops(NH#100, NH#101, ..., NH#115), all with weight: 16 except NHG#100 is of weight 1, in default VRF:

    • NH#100 with weight:1, pointing to 192.0.2.18

    • NH#101 with weight:16, pointing to 192.0.2.22

    • ...

    • NH#115 with weight:16, pointing to 192.0.2.79

• Validate with traffic:

  • NH10: (1/32) * (3/8) ~ 1.171% traffic received by ATE port-2 VLAN 1

  • NH11: (1/32) * (5/8) ~ 1.953% traffic received by ATE port-2 VLAN 2

  • NH100: (31/32) * (1/241) ~ 0.402% traffic received by ATE port-2 VLAN 3

  • for each VLAN ID in 4...18:

    • NH: (31/32) * (16/241) ~ 6.432% traffic received by ATE port-2 VLAN ID

  • A tolerance of 0.2% is allowed for each VLAN for now, since we only test for 2 mins.

Config Parameter Coverage

N/A

OpenConfig Path and RPC Coverage

paths:
  ## State Paths ##
  /network-instances/network-instance/afts/next-hop-groups/next-hop-group/next-hops/next-hop/state/weight:

rpcs:
  gnmi:
    gNMI.Get:
    gNMI.Set:
    gNMI.Subscribe:
  gribi:
    gRIBI.Get:
    gRIBI.Modify:
    gRIBI.Flush:

Minimum DUT platform requirement

• vRX - virtual router device

OpenConfig Path and RPC Coverage

The below yaml defines the OC paths intended to be covered by this test. OC paths used for test setup are not listed here.

paths:
  ## Config paths: N/A

  ## State paths:
  /network-instances/network-instance/afts/next-hop-groups/next-hop-group/next-hops/next-hop/state/weight:

rpcs:
  gribi:
    gRIBI.Get:
    gRIBI.Modify:
    gRIBI.Flush: